JPH01309193A - Bar code structure - Google Patents

Abstract

PURPOSE:To execute the reading of a bar code with high accuracy even when a distance between the bar code and a reading device is prolonged by forming the bar code on a substrate, for which a directional reflectivity is optically high, by utilizing plural fine transparent spherical body so that the reflectivity can be almost equal visually. CONSTITUTION:A substrate 21, for which the directional reflectivity is optically satisfactory, is composed of the cloth of soft or hard synthetic resin or a thin film. A transparent spherical body 22 is composed of synthetic resin or a glass material, whose diameter l is 10-100mu, for example, and the plural spherical bodies are finely fixed on the surface of the substrate 21 at random by adhesive 23. A bar code 24 is formed by an impermeable substance (an area 25a corresponds to the black print of the bar code) so that the surface color of the substrate 21 or the visual reflectivity to a diffused light can be almost equal. Thus, even when the distance between the bar code and reading device is prolonged, the reading of the bar code can be executed with the high accuracy.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a barcode structure used in product distribution, product management, etc., and in particular improves the directivity of reflected light relative to the amount of incident light and increases the amount of reflected light. The present invention relates to a barcode structure that improves barcode reading granularity and allows barcodes to be read easily from a relatively long distance and with high precision in a specific direction, for example.

(Prior Art) Conventionally, a barcode structure has a configuration in which a plurality of black and white bars of a predetermined width are arranged side by side on a flexible or rigid substrate surface. When reading a barcode, use a laser beam such as a semiconductor laser or H6-N laser to scan the barcode surface along the bar arrangement direction, or manually scan the barcode side instead of scanning the barcode surface. Scanning or automatic scanning is performed, and the reflected light from the barcode side at this time is received by a light receiving element such as a COD and converted into an electrical signal.

In order to improve the reading granularity of conventional barcode reading devices, it is necessary to increase the amount of light from the light source and to improve the optical performance of the light projecting optical system and the light receiving optical system.

However, attempts to satisfy these requirements tend to make the entire device more complex and larger.

Furthermore, it is generally difficult to increase the amount of light reflected from barcodes due to their structure, and for this reason, it has not been possible to increase the distance between the barcode and the reading device very much.

In addition, traditional barcodes are inefficient because they consist of a black and white pattern that can be read from any direction, for example, they can be read in a certain direction and are usually difficult to read in a different direction. It was difficult to configure it so that it could be read with a high degree of rust.

(Problems to be Solved by the Invention) The present invention uses a transparent sphere of a predetermined shape to form a barcode on a substrate surface with good optical directional reflectance, so that it is normally difficult to identify the barcode. When reading, the bar code and reading device improve the directionality of the reflected light from the reflective area corresponding to the white area of the bar and increase the amount of reflected light without increasing the amount of light from the light source in a specific direction. The object of the present invention is to provide a barcode structure that allows a barcode to be read with a high degree of opening even if the distance between the barcode and the barcode is increased, for example, from about 1m to 1m50cm.

(Means for solving the problem) When fixed to a substrate surface with optically high directional reflectance, the reflectance is visually approximately equal to that of the substrate surface for diffused light. The barcode was formed using multiple microscopic transparent spheres.

In addition, in the present invention, a plurality of minute transparent spheres are tightly fixed with adhesive on a substrate surface with optically directional reflectance,
The present invention is characterized in that a barcode made of a light-opaque material whose directional reflectance is visually approximately equal to that of the substrate surface is provided through the transparent sphere.

(Embodiment) FIG. 1 is a schematic diagram of an embodiment in which the barcode structure of the present invention is applied to a barcode reading device.

In the figure, reference numeral 1 denotes a light source, which is composed of a semiconductor laser, H, -Na laser, or the like. Reference numeral 2 denotes a condensing lens which condenses the light beam from the light source 1 into a predetermined spot diameter and guides it to a polygon mirror 3 serving as a scanning means. The polygon mirror 3 reflects the light beam and makes it incident on the area 6 on the surface of the barcode structure 4 where the barcode 5 is provided. The polygon mirror 3 rotates at a constant speed in the direction of the arrow 3a,
This allows the area 6 to be optically scanned. The barcode structure material 4 has a property of reflecting reflected light in a predetermined direction with high directivity with respect to the incident light beam, as will be described later. A condensing lens 7 condenses the reflected light from the barcode 5 and makes it incident on the surface of the pinhole plate 8. Reference numeral 9 denotes a light receiving element, which is composed of, for example, a photosensor, a photomultiplier tube, etc., and receives the light beam that has passed through the opening 8a of the pinhole plate 8. Reference numeral 10 denotes a calculation means which reads the barcode 5 using optical signals outputted in time series from the light receiving element 9.

In this embodiment, a light beam from a light source 1 is imaged by a condensing lens 2 via a polygon mirror 3 in the vicinity of a region 5 on a surface of a barcode structure 4.

By rotating the polygon mirror 3, the area 6 is optically scanned in the direction of the arrow 6a. Reflected light based on the code information of the barcode 5 is collected by a condenser lens 7, and is received by a light receiving element 9 via a hole plate 8.

Light 43 is outputted in time series from the light receiving element 9.
The barcode 5 is read by the computing means 10 using the number.

In this embodiment, the scanning system (polygon mirror 3) can be omitted by moving the barcode structure 4 in the direction of the arrow 6a instead of optical scanning.

FIGS. 2A and 2B are a perspective view and an enlarged sectional view of a first embodiment of the barcode structure of the present invention. In the figure, reference numeral 21 denotes a substrate with good optical directional reflectance, and is made of soft or rigid synthetic resin or thin film fabric. 22
The spheres are transparent spheres made of synthetic resin or glass and have a diameter 1 of, for example, about 10 to 100 μm, and are tightly and randomly fixed to the surface of the substrate 21 with an adhesive 23 . 24
is a barcode, which is formed of an opaque material (the area 25a corresponds to the black pattern of the barcode), and is formed so that the blood color of the substrate 21 or the visual reflectance to diffused light is approximately equal. There is.

The adhesive 23 contains a highly reflective material so that the luminous flux is reflected at a high reflectance at the bonding surface between the adhesive and the transparent sphere.

The barcode structure of this embodiment has a region 2 for diffused light.
Since the intensity of the light beam incident on the light beam 5b and the light beam reflected from the transparent sphere 22 and the light beam reflected from the light-opaque material in the area 25a are approximately equal, it is difficult to read the barcode 24.

In this embodiment, when a condensing light beam or a parallel light beam is incident on the barcode structure, the light beam that is incident on the area 25a corresponding to the black pattern of the barcode is reflected in a predetermined direction. Alternatively, the light is absorbed so as to have a low reflectance with respect to the substrate 21.

Furthermore, after the light flux incident on the area 25b corresponding to the self-pattern is reflected within the transparent sphere 22, it is efficiently emitted with a high reflectance in substantially the same direction as the incident light flux, and is detected by the light receiving system shown in FIG. are doing.

In this way, in this embodiment, by appropriately setting the configurations of the substrate 21, the transparent sphere 22, and the barcode 24,
By specifying the light beam incident on the barcode, it is possible to read it extremely clearly, which is visually difficult to read under normal lighting.

In addition, the reflected light from the barcode is efficiently emitted in the direction of incidence, thereby improving reading accuracy and reducing the overall size of the device.

FIG. 3 is an explanatory diagram showing the optical path of light incident on one transparent sphere 22a provided on the surface of the substrate 21 in FIG. 2. FIG. In the figure, 30 is the center of the transparent sphere 22a. Now, the refractive index of the medium on the incident side of the incident light beam is n! , when the refractive index of the medium of the transparent sphere 22a is 02, and the angle of incidence of the incident light beam onto the transparent sphere 22a is 11, the refraction angle 12 is sin i2 n 1 . Since the adhesive 23 containing a highly reflective material is provided on the outside of the transparent sphere 22a, the refracted light beam L' is reflected at one point 31 on the transparent sphere, and then from another point 32 in the incident direction at an exit angle i3. eject.

In this embodiment, the shape of the transparent sphere 22a is set as described above, so that fine barcodes can be easily formed, and the incident light is efficiently refracted and reflected and emitted in the direction of incidence, resulting in high precision. It is possible to read.

FIG. 4 is an enlarged sectional view of a second embodiment of the barcode structure of the present invention. In this embodiment, a transparent protective film 25 is provided on the surface of the transparent sphere 22, and a barcode 24 having the same characteristics as described in 1) η is provided on the surface of the protective film 25.

The protective film 25 is made of synthetic resin, glass, or the like. Providing the protective film 25 stabilizes the adhesion of the transparent sphere 22 and facilitates the formation of finer barcodes.

FIG. 5 is an enlarged perspective view of a third embodiment of the barcode structure of the present invention. In the figure, reference numeral 51 denotes a substrate with high directional reflectance, and is made of, for example, a white background plate with diffusive properties. Reference numeral 52 denotes a barcode, of which a region 52a corresponds to a self-pattern, in which a plurality of minute transparent spheres 53 are tightly and randomly fixed with an adhesive or the like to form a band-like pattern. Among these, the barcode is constructed by utilizing the reflection characteristics of the transparent sphere 53.

In this embodiment, when diffused light such as natural light is incident on the barcode structure, the area 52b where the transparent sphere 53 is not provided on the surface of the substrate 51 and the area 52a where the transparent sphere 53 is provided will each have similar diffuse reflection. This causes barcode reading to become difficult. On the other hand, a barcode structure is placed in the apparatus shown in FIG. 1, and a condensing light beam or a parallel light beam is incident from an oblique direction from a light projection means. Then, the light beam incident on the area 52b corresponding to the black pattern is reflected with high brightness in the reflection direction and does not return to the light receiving means at all.

On the other hand, the light beam incident on the area 52a corresponding to the own pattern undergoes multiple reflections as shown in FIG. 3, is strongly reflected in the direction of the incident light beam, and returns to be detected by the light receiving means. This allows the barcode 52 provided on the surface of the substrate 51 to be read.

In this embodiment, the substrate 51 is made of a material with a high directional reflectance having hues such as red, green, and blue, and correspondingly, the transparent sphere 0 is made of a material with the same hue as the substrate. If a color filter is used for reading, it becomes possible to multiplex a plurality of barcodes in the same area.

In each of the above embodiments, it is particularly preferable that the transparent sphere 2
2, the refractive index of the medium is n2, the refractive index of the medium on the light incident side is nl, and the diameter is 1, then l Oμ <
fi < 30μ...
・Axis - (1) 0, 3 < n2 - nl
It is preferable to configure it so that the conditional expression (2) is satisfied.

This allows the light incident on the transparent sphere to have a predetermined directivity, thereby configuring a barcode structure that can be read with high granularity.

When the range of conditional expressions (1) and (2) is exceeded, the directivity of reflected light decreases, and it becomes difficult to form fine barcodes.

In this example, when the transparent sphere is coated with a coating material such as transparent plastic or gelatin, the material is selected so that the difference in refractive index (n2-nl) between the coating material and the transparent sphere is 0.3 or more. It is better to configure the According to this, the light flux incident on the transparent sphere can be refracted and reflected, and then efficiently emitted in the direction of incidence.

In the second embodiment, the plurality of transparent spheres may be of the same size, or may be a collection of objects having the same size as a literary figure.

In the embodiment shown in FIG. 1, a sensor array such as a CCD is used as the light receiving element 9, and the light beam from the light source 1 is collected by the condensing lens 2.
It is also possible to irradiate the entire area 6 on the surface of the barcode 5, form an image of the barcode 5 on the surface of the light receiving element 9 with the condensing lens 7, and read the image of the barcode. According to this, the scanning system can be omitted and the entire apparatus can be simplified.

Further, if the light beam from the light source 1 is made to enter the barcode as a parallel light beam using a collimator lens, it is possible to read the barcode without providing a condensing lens on the light receiving side.

In addition, in this embodiment, a plurality of barcodes with completely different spectral characteristics (for example, a barcode consisting of red and a barcode consisting of green) are provided overlappingly on the surface of the transparent sphere 22, and a luminous flux having spectral characteristics matching them is provided. (Red light and green light) may be incident on each barcode, and the reflected light from the barcode may be received through a filter or the like that matches the spectral characteristics of each barcode.

According to this, a plurality of barcodes can be read simultaneously from within one area, and efficient reading becomes possible.

(Effects of the Invention) According to the present invention, by configuring a barcode by fixing transparent spheres having the above-mentioned characteristics on the substrate surface, incident light incident on the area corresponding to the reflective area of the barcode can be transparently transmitted. After being refracted and reflected within the sphere, it can be efficiently emitted toward the incident side, thereby increasing the amount of light detected by the light receiving element and increasing the distance between the barcode and the reading device. However, even if the distance is, for example, about 1 m to 1.5 m, it is possible to achieve a bar code structure that can read bar codes with high accuracy.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an embodiment of the barcode structure of the present invention applied to a barcode reading device, and FIG. 2(A)
, (11) are a perspective view and an enlarged sectional view of a first embodiment of the barcode structure of the present invention. FIG. 3 is an explanatory diagram of the optical path of light incident on a transparent sphere which is one element of the barcode structure of the present invention, and FIGS. FIG. 7 is an enlarged cross-sectional view of the third embodiment. In the figure, 1 is a light source, 2.7 is a condenser lens, 3 is a polygon mirror, 4 is a barcode structure, 5 is a barcode, 8 is a pinhole plate, 9 is a light receiving element, 10 is a calculation means, 21. 5
1 is a substrate, 22.53 is a transparent sphere, 23 is an adhesive, 24
．． 52 is a bar code, and 25 is protection ■q. Patent applicant Akira Kikuchi Science Institute Co., Ltd. 1
Figure 2 Figure (A) (B,) Figure 3

Claims (3)

[Claims] (1) A plurality of minute transparent spheres are placed on a substrate surface with high optical directional reflectance so that when fixed on the substrate surface, the reflectance for diffused light is visually approximately equal to that of the substrate surface. A barcode structure characterized in that a barcode is formed using. (2) The barcode structure according to claim 1, wherein the barcode is formed by tightly fixing a plurality of the transparent spheres on the surface of the substrate in a band shape using an adhesive. (3) A plurality of minute transparent spheres are tightly fixed with adhesive on a substrate surface that has an optically directional reflectance, and the directional reflectance is visually connected to the substrate surface through the transparent spheres. 1. A barcode structure comprising a barcode made of a light-opaque material that is equally transparent.